Out of nowhere strange things have been going on with my Camry's electric and what seemed harmless at first has gotten to the point where I'm having trouble getting it inspected. btw it's a 2001 v6 3.0l xle

Here's the run down of problems; they all kind of happened at the same time.
those these seem slightly unrelated I have a feeling they aren't / hoping you guys might be able to help me triangulate the issue if it's possible.

1) Dome Lights are no longer independent of each other / the roof light (back seat) used to do it's own thing regardless of what the push-button light above the front seats did. Now they only work together when the rear is in one of the three positions. And they barley work all; both are very dim/yellowy and will only work if the key is turned on or the car is running. (both used to work without key)

2 ) My in-dash stereo 'died' randomly / it's a pioneer CD player; not the fuse- Tested this deck in my van and it works fine. of course checked the wiring and power is everywhere it's supposed to be. Pulled my other cd player from my van (its a smaller one DIN; so maybe draws less power?) and put it into the Camry and it will run it for a little bit then it cuts out and loses power then after a few seconds it starts again. So the power intensity, I guess, is at the very least inconsistent or maybe intermittent. I will prob end up really monitoring those wires to see if there's any voltage fluctuations.

3) This is the worst one; code p1300 / no.1 Ignition coil keep tripping 'Check Engine' Light - have switched all the coils around and checked connections. Still trips regardless of what Ignition coil s in what spot. 12v going to each coil - my next idea is to switch the spark plugs in the front and see if the same thing happens...

What I've done so far / just replaced the battery / it was gettign leaky and showing corrosion thought maybe this was it / no difference to any of the above- It's not the alternator; it's brand new and I had it checked by the dude who replaced the battery just in case.

im running out of ideas. I'd be grateful for any points of light you could point me at. thanks

 

Check voltage at red wire of dome lights. Ditto for 12v ign power and the always hot 12v wires going to the radio. For Camry wiring this is gray and blue/yellow wires. All voltages should be battery voltage engine off.

Check the ohm resistance for dome and radio ground wires.

P1300 is Igniter Circuit Malfunction
Open/short in IGF or IGT circuit from igniter to ECM (wiring between igniter and ECM), igniter or ECM. Suppose a low voltage issue might cause this code.

Dome lights are powered via the integration relay.

 

Thanks for the reply Joey,
The voltage from the green (key on) is just over 12 volts. Straight battery
The gray/blue/yellow you mentioned, which should always be on is running around 5volts and only with key on.
The dome light is about the same; 4.92v. The Ohms (if I measured this right... ground chassis to ground tab of bulb holder) settled to 1.4ohms

okay a couple more bits to add
this one is directly related to the IC- I changed the connectors on 'No. 1' Ignition coil today which if I understand this right the middle one? (running spark plugs 1, 4) please correct me if I'm wrong... either way it made no difference. I cleared the code and it came back on; which leads me to another funny pattern...
The code (p1300) will trip from starting and shutting the engine off exactly three times. Regardless if I drive anywhere. I can drive all over on the second start with no CE light. As soon as I turn it back on after shutting off; there's the light.
Also the sunroof used to work for a bit, after shutting the car off, without the key on; same as all the windows, where it gives you a little time to close them before you exit. but now sunroof only works when key is all the way on.
Drive and Pass windows still work without the key; just as they always have.
Hope some of this helps...
thank you in advance!

 

A little more to add since yesterday -
Spent the morning better acquainting myself with the electrical schematics in the haynes manual and clumsily trying to trace the circuit from the battery to the dome lights/radio. Immediately I found a blown ECU-B fuse (10A) in the relay/fuse box above the driver side wheel. replacing it only pops a new one. even tried a 15A; same result.

So i'm hopeful I am on to something related def not having much luck finding what comes after this fuse or where to check.
What I've found online is mostly about the ECU-B is mostly about different model Toys and different year/generation camry's but there has been mention of it being related to the dome lights.

and one more thing that's new - The AC light (on the temp control panel) now blinks; it's never done this. Could be coincidence but I've come across a few mentions of 'compressor' bring tied into, or at least close, to the same circuit I'm digging around in.

 

Dome light voltages are too low.

Dome fuse powers the integration relay which powers the dome lights.

Find the Dome fuse and check voltage at hot side of fuse holder. Should be exact same as battery voltage.since fuse is connected to battery.

Sunroof receives power from Dome, Power, Door and Gauge fuses.

To try to narrow down the problem, check operation of the power window and power door locks.

Does the car have remote door locks and if so are they still working OK?

For P1300. The computer runs several checks which all must fail before setting a code. Check wiring between igniter and ECU.

 

The dome fuse in the box under the hood isnt putting out when the key is on. I can pull it and the interior lights work, though; as stated earlier are very dim. The 'Short pin', in the relay/fuse box is fine.

This might sound dumb but i am learning as i go.... the right terminal of the Dome fuse is actually continuous with both the neg and pos terminals on the battery. Does this mean there has to be a short before the fuse?

Doors and locks all work fine.

Found some schematics online, though more detailed than haynes, i think it's for the V4 because the integration relay (on the back of the fuse box) looks different/ with less inputs.. cant' seem to find my exact fuse box.

 

also the ECM-B fuse which pops fuses as soon as they are replaced (regardless of key) are continuous with BOTH battery terminals on it's positive side and the neg side of the fuse is continuous with only the neg side of the battery

 

The short pin is before the DOME and ECU-B fuses. If possible check for 12v at the short pin.

DOME and ECU-B fuses run to the fuse box containing the 100A ALT fuse. All fuses receive positive battery terminal power from a wire that runs to the box. All fuses are continuously powered.

The large 40A headlight fuse receives power from the same point as the DOME and ECU-B fuses.

If moving the DOME light fuses causes issues with dome power there could be a wiring issue in that fuse box. Demount the box from the chassis and check the wiring connections underneath which can corrode.

 

good call. just checked the fusable link and one side of it is continuous with both the pos and neg Battery terminals. and if this is the last link before the ECU-B and Dome it would explain why it's popping one and the other is dead right? (is the Dome fuse dependent on the ECU-b fuse?)

I completely removed the fuse block yesterday and looked over the wires and connectors but didnt see anything ugly. There's no corrosion, rust, or flaky wire coating I could see.

I've also downloaded the full service manual and am in the process of finding the layout for the underside of the fuse block. Or is there a way to get inside and check the internal routing? I can go get one from a junk yard for around $15. Thoughts?

 

todays update Pt 2:

I've been combing through a digital download I bought off ebay for 2001, supposedly. / found the fuse block disgram I am looking for however it's still not exactly for my car. Need to trace connections and I've been doing enough tail chasing without going down another rabbit hole with the wrong map.
Anyone have an exact match you could share?

here's the diagram I have and what I need would match the pics of the fuse block below.